There have been more Atmos 50 packs that have helped carry the gear of thru-hikers on the Appalachian Trail than any other pack! We don't really know if that's true or not, but it has to be close as Osprey's Atmos 50 blends the best in lightweight and superior comfort for up to 5 days on this world class trail.
The 50 liter capacity with an average weight of just over 3 lbs. means you can carry all you need and nothing you don't.
The Osprey Atmos 50 also features a top floating pocket/lid with twin front pockets for additional organization. Other features include an internal hydration sleeve, zippered mesh pockets on the adjustable hipbelt and removable sleeping pad straps.